A pedestrian believed to be in his 50s was killed early Tuesday morning when he was struck and became trapped under an SUV at an intersection in Long Beach, authorities said.

The collision was reported at 1:11 a.m. at Sixth Street and Park Avenue. The driver of the vehicle, an 82-year-old man, had a green light and was making a left turn at the time of impact, investigators said.

A Long Beach Police Department officer happened to be stopped at the intersection and saw part of the incident unfold. The SUV hit the victim, who was jogging through a crosswalk, and dragged him for about a block.

The officer "heard the thump, he looked to his left, he saw what looked like evidence of a collision, which may have been shoes in the intersection," police Lt. Melvin McGuire told reporters at the scene.

The policeman made a U-turn and followed the SUV, whose driver then pulled over. Despite rescue efforts to save the pedestrian's life, he was pronounced dead at the scene. He was not immediately identified.

The motorist and his passenger were cooperating with investigators, according to police. The driver was not immediately cited or arrested.